# Big Oak Plant

- **MSHA mine ID:** 4101126
- **Status:** Active
- **Type / commodity:** Surface / Sand, Industrial NEC
- **Location:** Bexar, TX
- **Operator:** Iron Oak Big Oak LLC
- **Controller:** Iron Oak Energy Solutions LLC
- **Public source rows linked:** 3,776
- **Source coverage:** 15 / 20
- **Generated:** 2026-10-13T11:26:59.401Z

## Current entity hierarchy

**Iron Oak Energy Solutions LLC (0189021) → Iron Oak Big Oak LLC (0092166) → Big Oak Plant (4101126)**

Current identity source: `msha-mines`. This is a current snapshot, not a historical claim.

## Controller and operator valid-time history

- **Clay M  Tooke → Osburn Materials Inc:** 1950-01-01 through 2017-04-12; derived from co-tenure at mine 4101126; source `msha-controller-operator-history`.
- **Insight Equity et al → Iron Oak Big Oak LLC:** 2017-04-13 through 2019-12-09; derived from co-tenure at mine 4101126; source `msha-controller-operator-history`.
- **Oak Hill Advisors et al → Iron Oak Big Oak LLC:** 2019-12-10 through 2025-12-15; derived from co-tenure at mine 4101126; source `msha-controller-operator-history`.
- **PIMCO et al → Iron Oak Big Oak LLC:** 2019-12-10 through 2025-12-15; derived from co-tenure at mine 4101126; source `msha-controller-operator-history`.
- **HPS Investment Partners et al → Iron Oak Big Oak LLC:** 2019-12-10 through 2025-12-15; derived from co-tenure at mine 4101126; source `msha-controller-operator-history`.
- **Iron Oak Energy Solutions LLC → Iron Oak Big Oak LLC:** 2025-12-16 through current/open; derived from co-tenure at mine 4101126; source `msha-controller-operator-history`.

- History rows: 6
- Typed edges: 12
- Interval anomalies: 0
- Valid-time bounds: inclusive; date granularity; null end means open-ended in the upstream history row; not independent proof of present control.
- Transaction-time observation: 2026-10-13T11:19:05.459773+00:00.

## Assessment signals

1. **SAFETY — 10 since 2021:** Accidents and injuries 22 historical accident/injury rows; 2 coded fatalities and 73 lost days across the published record.
2. **COMPLIANCE — 202 since 2021:** Violations and penalties 340 violation rows across the full record; 86 carry an S&S flag and $267,716 appears in current assessed amounts.
3. **HEALTH — 24 samples:** Occupational health samples 24 personal. 2 personal-sample rows have a published C/E ratio above 1; 0 noise rows have an action-level or PEL dose above 100%. These are separate measures, not a silica exceedance count. Silica results and sample status are shown separately.
4. **PRODUCTION — 0 tons:** Quarterly production and employment 70K employee hours and 90 summed average employees across reported subunits in the latest published quarter.
5. **LEGAL — 25 linked rows:** Contests, conferences and decisions 10 contested-violation rows, 8 civil-penalty docket/decision rows, and 7 conference records linked by issuance number.
6. **CONTRACTORS — 15 linked entities:** Contractors Contractors are linked through this mine’s violation or accident records. Their production and hours cover all their operations, so they are not included in this mine’s totals.
7. **INSPECTIONS — 37 since 2021:** Inspections 103 inspection events and 2K published inspection hours across the historical record.

## EIA annual operating context

No matched record in the 2024 EIA coal-public workbook. This may be inapplicable for a non-coal operation.

## Recent Title 30 crosswalk

Snapshot current through 2026-08-19.

- **30 CFR 56.14100 — Safety defects; examination, correction and records.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-M/section-56.14100
- **30 CFR 56.4201 — Inspection.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-C/section-56.4201
- **30 CFR 56.4200 — General requirements.** (2 retained recent rows) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-C/section-56.4200
- **30 CFR 50.20 — Preparation and submission of MSHA Report Form 7000-1—Mine Accident, Injury, and Illness Report.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-I/part-50/subpart-C/section-50.20
- **30 CFR 46.3 — Training plans.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-H/part-46/section-46.3
- **30 CFR 46.9 — Records of training.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-H/part-46/section-46.9
- **30 CFR 56.12008 — Insulation and fittings for power wires and cables.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-K/section-56.12008
- **30 CFR 56.11003 — Construction and maintenance of ladders.** (2 retained recent rows) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-J/section-56.11003
- **30 CFR 56.14107 — Moving machine parts.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-M/section-56.14107
- **30 CFR 56.12032 — Inspection and cover plates.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-K/section-56.12032

## Source coverage

- **Accident, Injuries, and Illnesses:** 22 rows; 2005-09-06 through 2025-06-04; source ID `msha-accidents`
- **Addresses of Record:** 1 rows; 1976-07-04 through 1976-07-04; source ID `msha-addresses`
- **Assessed Violations:** 331 rows; 2000-04-19 through 2025-11-13; source ID `msha-assessed-violations`
- **Civil Penalty Dockets and Decisions:** 8 rows; 2011-06-23 through 2020-01-23; source ID `msha-civil-penalty-dockets-decisions`
- **Conferences:** 7 rows; 2004-11-02 through 2024-03-26; source ID `msha-conferences`
- **Contested Violations:** 10 rows; 2010-09-28 through 2019-12-09; source ID `msha-contested-violations`
- **Contractor Employment and Production — Quarterly:** 2,146 rows; unknown through unknown; source ID `msha-contractor-production-quarterly`
- **Contractor Employment and Production — Yearly:** 508 rows; unknown through unknown; source ID `msha-contractor-production-yearly`
- **Controller and Operator History:** 6 rows; 1950-01-01 through 2017-04-13; source ID `msha-controller-operator-history`
- **Inspections:** 103 rows; 2000-04-19 through 2026-09-14; source ID `msha-inspections`
- **Mine Employment and Production — Quarterly:** 215 rows; unknown through unknown; source ID `msha-mine-production-quarterly`
- **Mine Employment and Production — Yearly:** 54 rows; unknown through unknown; source ID `msha-mine-production-yearly`
- **Mines:** 1 rows; unknown through unknown; source ID `msha-mines`
- **Metal and Nonmetal Personal Health Samples:** 24 rows; 2001-09-12 through 2025-11-13; source ID `msha-personal-health-samples`
- **Violations:** 340 rows; 2000-04-19 through 2025-11-13; source ID `msha-violations`

## Caveats

- This is public-record decision support, not legal advice or an official MSHA record.
- Missing data can indicate no event, publication delay, an unresolved identity, or inapplicability.
- Contractor production data is entity-level and is not attributed to this mine.

## Alternate representations

- HTML: `/mines/big-oak-plant-4101126`
- JSON: `/api/v1/mines/big-oak-plant-4101126`
- Silica records, units, sample status and quarterly means: `/api/v1/mines/4101126/silica` (snapshot year by default; `?year=all` for history; `&format=csv` for all matching rows)
- Relationship JSON: `/api/v1/mines/4101126/relationships`
- MCP resource: `mine://4101126/assessment`
- Complete Title 30 corpus: `/data/title30-sections.json`